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981.
In this paper, we derive the Bayes estimator of the location parameter in double-exponential family under the LINEX loss function, and then construct the corresponding empirical Bayes estimator. It is shown that the empirical Bayes estimator is asymptotically optimal with convergence rate being , , where 1/2相似文献   
982.
目的 从代谢组学角度分析并寻找2型糖尿病(T2DM)患者可能的代谢标记物。方法 选取30例初诊、或有糖尿病史经药物治疗控制不理想且无并发症的T2DM 患者,另选取30例性别、年龄匹配的健康者为正常对照。收集清晨空腹中段尿,以气相色谱- 质谱联用(GC-MS)技术对尿液样本进行代谢图谱分析,正交偏最小二乘法判别研究尿液内源性化合物在两组间的差异。结果 T2DM 组和正常对照组尿液代谢谱明显分离。与正常对照组比较,T2DM 组尿液2,3,4- 三羟基丁酸、肌醇、D- 葡萄糖、D- 葡萄糖酸及尿素含量升高(P<0.05 或0.01),马尿酸含量减少(P<0.01)。结论 代谢组学检查提示T2DM 患者尿液中代谢标志物为2,3,4- 三羟基丁酸、肌醇、马尿酸、D-葡萄糖、D- 葡萄糖酸及尿素,观察这些标志物含量的变化有助于T2DM 的临床诊断及发病机制研究。  相似文献   
983.
肖飞  徐文平  张望平  张小敏  王立中 《应用数学》2015,37(4):321-323,332
目的 探讨重度子痫前期产妇剖宫产重比重布比卡因蛛网膜下腔阻滞麻醉(腰麻)的适合剂量。方法 选取200例重度子痫前期产妇,ASAⅠ级或Ⅱ级,按随机数字表法分为4组,每组各50 例,相应各组鞘内注入布比卡因剂量分别为10、8、6 及4mg,并混合2.5μg 舒芬太尼。选择L3~4行腰硬联合穿刺,注药10min 后记录麻醉平面。根据结果进行Probit 回归分析,计算布比卡因腰麻的ED50和ED95。观察各组利多卡因及去氧肾上腺素的用量、肌松效果及患者麻醉满意度,观察各组术中并发症以及新生儿的Apgar 评分和脐动脉pH。结果 重度子痫前期患者腰麻剖宫产布比卡因ED50 和ED95分别为:6.51(95%CI:5.81~7.01)和8.68(95%CI:7.96~10.26)。4 组患者10min 后麻醉平面的差异均有统计学意义(均P<0.05)。4mg 组利多卡因用量高于其他3组,差异有统计学意义(P<0.05)。8mg 组、10mg 组去氧肾上腺素的用量高于其他两组,差异均有统计学意义(均P<0.05)。低血压的发生率8mg 组、10mg 组高于其他两组,差异均有统计学意义(均P<0.05)。4 组间其他不良反应恶心、呕吐、寒战以及心动过缓发生率的差异无统计学意义(P>0.05)。4 组胎儿娩出后1、5min Apgar 评分及脐动脉血气分析的结果差异均无统计学意义(均P>0.05)。结论 重度子痫前期产妇剖宫产鞘内注入6mg 布比卡因混合2.5μg舒芬太尼,必要时辅以硬膜外麻醉,麻醉效果确切,血流动力学稳定,适合该类患者手术麻醉。  相似文献   
984.
We evaluate the non-Markovian effects on the entanglement dynamics of a fermionic system interacting with two dissipative vacuum reservoirs. The exact solution of density matrix is derived by utilizing the Feynman–Vernon influence functional theory in the fermionic coherent state representation and the Grassmann calculus, which are valid for both the fermionic and bosonic baths, and their difference lies in the dependence of the parity of the initial states. The fermionic entanglement dynamics is presented by adding an additional restriction to the density matrix known as the superselection rules. Our analysis shows that the usual decoherence suppression schemes implemented in qubits systems can also be achieved for systems of identical fermions, and the initial state proves its importance in the evolution of fermionic entanglement. Our results provide a potential way to decoherence controlling of identical fermions.  相似文献   
985.
Let G =(V,E) be a simple graph.For any real function g :V-→ R and a subset S V,we write g(S) =∑v∈Sg(v).A function f :V-→ [0,1] is said to be a fractional dominating function(F DF) of G if f(N [v]) ≥ 1 holds for every vertex v ∈ V(G).The fractional domination number γf(G) of G is defined as γf(G) = min{f(V)|f is an F DF of G }.The fractional total dominating function f is defined just as the fractional dominating function,the difference being that f(N(v)) ≥ 1 instead of f(N [v]) ≥ 1.The fractional total domination number γ0f(G) of G is analogous.In this note we give the exact values ofγf(Cm × Pn) and γ0f(Cm × Pn) for all integers m ≥ 3 and n ≥ 2.  相似文献   
986.
A new family of univariate exponential slash distribution is introduced, which is based on elliptical distributions and defined by means of a stochastic representation as the scale mixture of an elliptically distributed random variable with respect to the power of an exponential random variable. The same idea is extended to the multivariate case. General properties of the resulting families, including their moments and kurtosis coefficient, are studied. And inferences based on methods of moment and maximum likelihood are discussed. A real data is presented to show this family is flexible and fits much better than other related families.  相似文献   
987.
988.
Abstract

A series of 2-methylpropan-2-aminium methyl 1-(substituted phenoxyacetoxy) alkylphosphonates were selectively synthesized by reacting the corresponding dimethyl 1-(substitutedphenoxyacetoxy)alkylphosphonates with an excess of 2-methylpropan-2-amine. All the title compounds were identified by IR, 1H NMR, and 31P NMR, some of them were further analyzed by 19F NMR and 13C NMR. Their herbicidal activity was investigated and the results showed that most of the demethylated aminium salts exhibited notable herbicidal activities against Brassica napus L. and Echinochloa crusgalli.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional text, figures and tables.  相似文献   
989.
990.
The analysis on the recovery performance and characteristics in shape memory effects is helpful for the optimal design and engineering applications of shape memory polymers and their composites. To investigate the relationships among recovery performance, material parameters, and loading conditions, by taking aliphatic polyether urethane as an example, the researchers simulate the shape memory behaviors numerically using a three‐dimensional viscoelastic model. The material parameters for this model are taken from stress relaxation tests, rather than dynamic mechanical analysis tests. Both the unconstrained and the constrained recovery behaviors during strain‐controlled shape memory processes are analyzed. The results reveal that the unconstrained recovery occurs at the same temperature regardless of the applied strain values. Another interesting result is that the shape recovery temperature in unconstrained recovery situations increases and the maximum recovery stress under constrained recovery conditions decreases with the increase of heating rates. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
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